package br.ufpe.cin.dmo4.middleware.io;

import java.io.IOException;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.ObjectOutputStream;
import java.io.ObjectInputStream;

/**
 * Utility for making deep copies (vs. clone()'s shallow copies) of objects.
 * Objects are first serialized and then deserialized. Error checking is fairly
 * minimal in this implementation. If an object is encountered that cannot be
 * serialized (or that references an object that cannot be serialized) an error
 * is printed to System.err and null is returned. Depending on your specific
 * application, it might make more sense to have copy(...) re-throw the
 * exception.
 */
public class DeepCopy {

    /**
     * Returns a copy of the object, or null if the object cannot be serialized.
     */
    public static Object copy(Object orig) {
        Object obj = null;
        try {
            // Write the object out to a byte array
            FastByteArrayOutputStream fbos
                    = new FastByteArrayOutputStream();
            ObjectOutputStream out = new ObjectOutputStream(fbos);
            out.writeObject(orig);
            out.flush();
            out.close();

            // Retrieve an input stream from the byte array and read
            // a copy of the object back in. 
            ObjectInputStream in
                    = new ObjectInputStream(fbos.getInputStream());
            obj = in.readObject();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException cnfe) {
            cnfe.printStackTrace();
        }
        return obj;
    }

    public static Object deserializeObject(byte[] array) throws IOException, ClassNotFoundException {
        FastByteArrayOutputStream fbos
                = new FastByteArrayOutputStream();

        fbos.write(array);

        // Retrieve an input stream from the byte array and read
        // a copy of the object back in. 
        ObjectInputStream in
                = new ObjectInputStream(fbos.getInputStream());
        Object obj = in.readObject();

        return obj;
    }

    public static byte[] serializeObject(Object obj) throws IOException {
        FastByteArrayOutputStream fbos
                = new FastByteArrayOutputStream();
        
        ObjectOutputStream out = new ObjectOutputStream(fbos);
        out.writeObject(obj);
        out.flush();
        out.close();
        
        return fbos.getByteArray();
    }

}
